Light transparent container inspecting apparatus



July 22, 1969 v, s p EIAL LIGHT TRANSPARENT CONTAINER INSPECTINGAPPARATUS Filed July 10, 1967 FIGJ.

mm 5 mm NSN m o B w M 3 gm G m .l v Cl MM W 3 u? w J a u m a 4 w 33,456,788 LIGHT TRANSPARENT CONTAINER INSPECTING APPARATUS Virgil MelvinStapf, St. Louis, and Momir Babunovic,

Des Pere, Mo., assignors to Barry-Wehmiller Company, St. Louis, Mo., acorporation of Missouri Filed July 10, 1967, Ser. No. 652,215 Int. Cl.B07c /34; H01j 39/12; G06m 5/10 U.S. Cl. 209111.7 3 Claims ABSTRACT OFTHE DISCLOSURE Inspecting apparatus for light transparent containers inwhich light intensity sensitive means is applied to the work of rapidlyand continuously looking at successive containers to determine if anycontainer should be rejected for any of a number of reasons, such asbeing excessively scuffed.

This invention relates to inspection apparatus for determiningparticular characteristics or conditions in respect of light transparentcontainers, and is more particularly concerned with improvements inapparatus for inspecting containers for such conditions as excessivescuffing of the exterior surfaces thereof.

A particularly troublesome condition with transparent containers,including those made of glass as well as plastic, is that after a periodof usage and rough treatment in commercial handling, certain fairly welldefined exterior surfaces become scuffed and abraded to such an extentthat it detracts from the appeal that the container makes to thepurchasing public and actually causes loss of sales. On the other hand,the public image developed by the manufacturers beverage products beingdispensed in clean non-shabby looking containers induces a readyacceptance on the part of the purchaser, as opposed to the shabby,unattractive appearance of beverage products that are contained inscuffed and abraded containers. It has been shown that the clean lookingcontainers that impart a certain degree of sparkle or freshness to thecontents will sell much more readily than a container that is dull anddoes not present the contents in an inviting manner.

A particularly important object of the present invention is to providerelatively simple, trouble-free inspecting apparatus that is both usefuland novel in connection with inspecting containers for surface scuff andabrasion characteristics.

It is also an important object of the present invention to provide asimple and economical electronic system for cooperation withphotovoltaic cells so as to provide reliable means to be coupled withequally reliable and economical mechanical means for determining, wtihrespect to transparent containers, acceptable from unacceptable scuffand abrasion surface conditions.

A further object of the present invention is to provide an inspectingapparatus that will respond to variations in intensity of lightprojected through the container and produce a voltage output which isdirectly proportional to the difference between the acceptable andunacceptable characteristics of the container.

Yet another object of the present invention is to provide inspectingapparatus in which light is projected at containers passing aninspection zone and means is positioned opposite the light source torespond to the difference in the intensity of the light passing throughdifferent portions or areas of each container so as to produce a changein voltage which may be suitably utilized for actuating other means toeliminate the unwanted container from those that are determined to beacceptable.

Sttes Patent 0 3,456,788 Patented July 22, 1969 Other objects andattendant advantages of the present invention will be set forth in thefollowing disclosure of preferred embodiments of the inspectingapparatus, reference being made to the several views in the accompanyingdrawings, wherein:

FIG. 1 is a fragmentary and somewhat enlarged plan view of containerinspecting apparatus incorporating the present invention;

FIG. 2 is a fragmentary and greatly enlarged sectional elevational viewtaken at line 22 in FIG. 1;

FIG. 3 is a fragmentary developed plan view of the rotor member shown inFIG. 2; and

FIG. 4 is a simplified and schematic layout of the electronic systemherein preferred.

Referring now to FIGS. 1 and 2, it can be seen that a usual type oftable top conveyor chain belt 10 is provided with the usual side guides11 and 12 for conducting in single file order a series of containers Cto be inspected for external surface scuffing and abrasion conditions.The inspecting apparatus is illustrated by a rotary starwheel 13 whichis formed with suitable peripheral recesses 14 suited to fit thecurvature of the containers C. The starwheel 13 revolves about thecenter axis A and is positioned in relation to the linear travel of thecontainers on the conveyor 10 to pick up successive containers andregister the containers with the successive peripheral recesses 14. Therotary movement of the starwheel 13 is caused by the pressure of theincoming containers C and carries the containers toward the oppositeside guide 11 of the conveyor 10. As rotation continues beyond the pointof near approach of the containers to the side guide 11 the recess 14will then release the containers so as to allow them to travel again ina linear direction.

When each successive container reaches the position of container C-l itis in the inspection zone where a suitable frame 16 supports a source ofhigh intensity energy in the form of the light 17 and on the oppositeside of the container C1 there is an inspection unit 18 that containsthe inspection equipment presently to be described. The light source 17discharges a beam of light through which each container must pass. Ifthe container C1 is acceptable it will pass linearly along the conveyor10, but if it is unacceptable because of a too badly scuffed and abradedexterior surface, the starwheel 13, working in conjunction with asuction cup device 19 (FIG. 2), will carry the container across asuitable sta tionary deadplate 20 and into a reject accumulator table 21which rotates in a direction opposite to the direction of the starwheel13. The device 19 is similar to one disclosed in United States PatentNo. 2,800,226, issued July 23, 1957. Thus, a rejected container C-2 willbe removed from the flow of acceptable containers. In order to controlthe inspecting apparatus there is provided adjacent the frame 16 asuitable switch 22 having its feeler arm 23 positioned to engage eachcontainer as it is brought into the inspection zone and each containeractuates the switch 22 to its ON position to energize an amplifier,presently to be described, and the amplifier remains energized for apredetermined period of time. When this period of time has elapsed theamplifier for the unit 18 is shut off and remains so until the nextsucceeding container approaches the position of container C-l.

Looking at FIG. 1, it can be seen that approximately the centerone-third of each container is lighted due to the fact that as thatportion of the container indicated by the reference line G strikes thefeeler arm 23 it actuates switch 22 to the ON position. The containermoves on toward the right and when its portion indicated by referenceline H reaches the location of the feeler arm 23 it will allow the armto move to the OFF position. Between the portions G and H the containersurface is convex and is able to effect movement of the arm 23 becausethe container is firmly seated in its recess 14. Thus, during theillumination of the central portion of each container C1 the inspectingor looking for undesired surface conditions takes place.

In FIG. 2 there is shown the rotary starwheel 13 in association with anauxiliary starwheel 13 separated from each other by means of the suctioncup device 19 having a series of suction cups 19' corresponding witheach of the peripheral recesses 14 (FIG. 1). The starwheels 13 and 13'support the body and neck portions respectively of the containers, andfreewheel about the axis A on a suitable shaft 24. The container C-l isshown in the inspection station where the light source 17 produces asource of light on one side of the container -1. The light travelsthrough the container toward inspection unit 18 where the usable portionof the light is confined by a narrow but elongated slot (FIGS. 2 and 3).The slot is formed in the unit 18 so as to restrict the light beam to aselected vertical portion of the container where the undesired surfacedefects usually occur. The height of the usable light beam B ineludes atleast a portion of the container that is not subject to surface defectsso that a valid comparison is obtained between good and bad surfaceconditions.

Within the unit 18 there is mounted an electric motor 26 connected tothe hub 27 of an inverted cup shaped rotor 28 having a series ofsequentially arranged and stepped apertures therein. The apertures aresuccessively passed across the beam of light admitted by the slot 25,and within the rotary cylinder 28 there is positioned a photovoltaic,selenium type, photocell 38*. The photocell 30 is suitably supportedfrom the base of the unit 18 and is electrically associated with acircuit which is responsive to the change in voltage output of thephotocell 30.

As shown in FIG. 3, the rotor 28 when shown in developed view provides aconsecutive series of apertures 31a, 31b, 31c, 31d and 31s. Asindicated, the apertures do not have to be regularly arranged, butapertures 31b and 31d may, for example, be located in the broken outlinepositions. Each aperture of the sequence has the same physical size sothat there will be substantially no diflerence in the amount of lightthat is admitted to strike the photocell 30. Each aperture sweeps acrossthe vertical slot 25 at least once during the time the central portionG-H of each container is in front of the light source 17. More than onesweep can be obtained by properly speeding upthe rotation of rotor 28.

As the individual containers, such, for example as container C-l,proceeds from left to right under the feeler 23 of the switch 22, itwill actuate switch, 22 and that, in turn, will activate the detectionelectronic system shown schematically in FIG. 4. Each container isinspected during the time that control switch 22 is activated, which isto say between the time the central portion of each container moves fromthe position denoted at G to the position where the portion H reachesthe position first reached by the portion G. During the time involved inthis container movement it is necessary that the rotary cylinder 28 inthe inspection unit 18 revolve fast enough to permit at least one sweepof the consecutive apertures 31a through 31a over the vertical limits ofthe viewing slot 25. This is necessary in order to permit the photocell30 to have a chance to respond to conditions over a representative areaof the exterior of the container that is usually subject to scufiing.

As the cylinder 28 rotates the photocell 30 receives light successivelyfrom 5 different levels along the axis or ength of the container C-1,and if there is an insignificant change in the direct current voltageoutput the electric system interprets this result to accept thecontainer as being satisfactory. Five apertures are shown, but less ormore apertures may be provided. An acceptable container, therefore,develops a substantially unvarying or steady voltage response from thecell 30 during the inspection time. The inspection apparatus also takescare of the possibility that at least one of the successive apertures31a through 312 would see the portion of the container with good lighttransmission characteristics and at least one of these apertures wouldsee the portion of the container with poor light transmissioncharacteristics. In this situation the photocell 30 undergoes a changein its voltage output. The change in voltage is transmitted to anamplifier device which amplifies this change in voltage and causes arelay to be actuated. The relay actuation is then transmitted through asuitable means (not shown) which applies vacuum to the associated vacuumcup 19' whereby the container to be rejected is retained in its recesson the starwheel 13 until it has reached the area over the rejectaccumulator table 21.

It is important to realize that the same photocell is used for all ofthe looks that are made through the successive apertures 31a through31c, whereby it is always comparing its own voltage changes as it isexposed to a source of light whose changing condition is directlygoverned by acceptable or unacceptable condition of transparency (lighttransmittability) of the container. Thus the present improvement in theelectronic system automatically eliminates many of the inherent problemsusually encountered, such as changes between two different photocellsdue to changes in temperature, humidity, power line voltage variationsand similar conditions.

Turning now to FIG. 4, the photocell 30 is schematically shown connectedto a photovoltaic or photoconductive intermediate circuit 32, and thiscircuit is connected to an amplifier and relay 33, such for example, asModule TR 4 manufactured by Farmer Electrical Products Co., Inc. ofMassachusetts. The amplifier and relay 33 is operatively connected tothe single pole double throw limit switch 22 which is utilized to turnon and to reset the amplifier and relay 33, as well as to allow a atimer 34 to start uniformly each time the control switch 22 (FIG. 1) isrendered inactive when its control feeler 23 reaches the position on thecontainer represented by the reference line H at the conclusion of eachcontainer inspection. Timer 34 controls the length of time that thesolenoid 35 is actuated, this solenoid being associated with a valve inthe vacuum line connected to the respective suction cups 19'. Thus, themovement of each container C1 through the inspection zone turns on theswitch 22 at G and turns it off at H. The distance, as previously noted,between G and H may comprise approximately the center one-third of eachcontainer. During the time switch 22 is in the ON position the containerC-1 is inspected or scanned for the particular defeet or objection thatcould cause it to be rejected.

If the container is rejected a reject signal will be picked up by theamplifier 33. The amplifier 33 energizes its relay which latches into alocked position and quickly charges up a capacitor in timer 34. When thecontainer leaves the inspection zone the switch 22 turns to the OFFposition. At this time the capacitor in timer 34 discharges andenergizes a relay to operate the solenoid 35 which opens a valve (notshown) in the suction cup unit 19. The suction cup 19' holds thecontainer in its recesses in starwheels 13 and 13 until it is over thereject table 21 where it is released by a suitable valve trip device.Simultaneously the relay in means 33 is deenergized and the amplifier isreset to repeat the foregoing cycle on the next container that isobjectionable.

As is suggested in FIG. 2, any difference in the intensity of light inany of the apertures 31a to 31e will produce a change in voltage outputof the cell 30 which is sensed by means 32. Any one of the apertures 31ato 31c may produce the highest voltage on the cell 30. This voltagereading is used as the reference voltage against which the readings fromthe remaining apertures is compared. Thus, it is important that at leastone aperture must always be arranged to scan the light passing through aclear or acceptable portion of the container while other apertures arearranged to scan the areas that may be objectionable in order to producethe maximum voltage change response from cell 30. It is also importantthat a zone of the container Where scufiing normally occurs shall bescanned during the time interval the one-third central portion G-H ofthe container diameter passes the inspection zone. The fixed light slot25 prevents any stray light from striking the cell 30 and this avoidsfalse reactions in the electrical system of FIG. 4.

In the foregoing apparatus, the response by the cell 30 to eachcontainer takes into account its color condition so that a clearcontainer will cause a higher level of voltage output than will a darkor more dense container. Thus, as containers change in color or densitythe cell 30 will sense the change in intensity of the light and merelyvary its voltage output in proportion, but for a container that needs tobe rejected the cell Will produce a significant change in voltage outputwithin the level of output caused by the light transmissibility of thecontainer then being inspected.

While a preferred embodiment of the present invention has been disclosedit is recognized that variant and equivalent means may be utilized topractice the principles hereof.

What is claimed is:

1. Container inspecting apparatus for selectively passing and divertinglight transparent containers including:

(1) a source of light;

(2) a light receiving unit spaced from said source of light;

(3) conveyor means moving containers in succession through the spacebetween said source of light and said light receiving unit;

(4) and means to receive containers diver-led by the inspectionapparatus; said light receiving unit comprising,

(a) a container scanning rotor formed with a plurality of scanningapertures located at different heights along the axis of the containers,

(b) a light sensitive cell disposed adjacent the path of movement ofsaid rotor scanning apertures to receive light directed through saidapertures from the containers (1) said cell being responsive to theintensity of the light received through said scanning apertures toproduce a voltage change proportional to the light intensity andindicative of the transparency condition of the containers, said voltageoutput being substantially uniform for containers to be passed andvarying for containers to be rejected,

(c) and means responsive to said varying voltage output to divertcontainers to said receiving means.

2. The apparatus set forth in claim 1 wherein said scanning rotor is acylindrical member having the scanning apertures in its peripheral Wall,and said light sensitive cell is disposed within said cylindricalmember.

3. The apparatus set forth in claim 2 and including a housing enclosingsaid cylindrical member, said housing being formed with an aperturealigned With said light source and admitting a predetermined portion ofthe light While excluding other portions of the light from passing tosaid cell.

References Cited UNITED STATES PATENTS 4/1953 Stoate 209--111.7 5/1968Mayeau 209-l11.7 X

US. Cl. X.R. 250223; 35 6240

